This talk presents the measurement of the lifetime of the B_s meson in proton-anti-proton collisions at 1.8 TeV using 110 pb-1 of data collected at CDF. The B_s signature is D_s-lepton correlations, where the D_s is reconstructed in three decay modes. The B_s meson proper lifetime distribution is examined for a lifetime difference between the two CP eigenstates of the B_s meson, B_s(L) and B_s(H).